Angiogenesis: New insights and therapeutic potential

Angiogenesis, the formation of vessels from pre-existing vessels, is of cri tical importance not only during normal growth, but also in pathological si tuations. in the latter, some diseases are enhanced by excessive vascular g rowth (e.g., tumors), whereas in others inadequate vascular growth contribu tes to morbidity and mortality (e.g., ischemic heart disease). Our current state of knowledge makes it clear that the cascade of angiogenic events dep ends on complex processes that include cell-cell interactions, various intr acellular signaling pathways, and the appropriate extracellular microenviro nment. The literature regarding angiogenesis has increased exponentially du ring the last decade. Progress in this area is largely a consequence of adv ances in our understanding of angiogenic growth factor and cytokine functio n, in part due to the determination of their complete amino acid sequences and cloning of their genes. Other factors also play key roles in angiogenes is, including the extracellular matrix, adhesion molecules and their inhibi tors, and metabolic and mechanical factors. The potential for developing th erapeutic protocols has been enhanced by data from both in vitro and in viv o studies and has provided the rationale for clinic trials. Angiogenic ther apy strategies include inhibition of aberrant angiogenesis, as seen in tumo rs or diabetes, as well as stimulation of angiogenesis in conditions of isc hemia, such as ischemic heart or peripheral vascular disease. Anat Rec (New Anat) 261:126-135, 2000. (C) 2000 Wiley-Liss, Inc.